fix: prevent My Apps crash when installing apps + add filebrowser to demo

The My Apps page went blank after installing apps because pkg['static-files'].icon
was accessed without optional chaining on dynamically installed packages that lack
the static-files property.

- Make static-files optional in PackageDataEntry type
- Add defensive ?.icon access with fallback in Apps.vue and AppDetails.vue
- Add filebrowser to mock backend staticDevApps (enables Cloud page in demo)
- Expand portMappings and marketplaceMetadata for all marketplace apps
- installPackage now uses staticApp() format for consistent data shape

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

neode-ui/src/types/api.ts

@@ -68,7 +68,7 @@ export type PackageState = typeof PackageState[keyof typeof PackageState]
 
 export interface PackageDataEntry {
   state: PackageState
-  'static-files': {
+  'static-files'?: {
     license: string
     instructions: string
     icon: string